- What is tadalafil, and how does it work (mechanism of action)?
- What brand names are available for tadalafil?
- Is tadalafil available as a generic drug?
- Do I need a prescription for tadalafil?
- What are the uses for tadalafil?
- What are the side effects of tadalafil?
- What is the dosage for tadalafil?
- Which drugs or supplements interact with tadalafil?
- Is tadalafil safe to take if I'm pregnant or breastfeeding?
- What else should I know about tadalafil?
What is tadalafil, and how does it work (mechanism of action)?
Tadalafil is an oral drug that is used for treating impotence (the inability to attain or maintain a penile erection) and benign prostatic hyperplasia (BPH). It is in a class of drugs called phosphodiesterase-5 (PDE5) inhibitors that also includes sildenafil (Viagra) and vardenafil (Levitra). Erection of the penis is caused by the filling of the penis with blood. Filling occurs because the blood vessels that bring blood to the penis increase in size and deliver more blood to the penis, and, at the same time, the blood vessels that take blood away from the penis decrease in size and remove less blood from the penis. Sexual stimulation that leads to an erection causes the production and release of nitric oxide in the penis. The nitric oxide causes an enzyme, guanylate cyclase, to produce cyclic guanosine monophosphate (cGMP). It is cGMP that is primarily responsible for increasing and decreasing the size of blood vessels carrying blood to and from the penis, respectively, and causing an erection. When the cGMP is destroyed by another enzyme, phosphodiesterase-5, the blood vessels return to their normal size, blood leaves the penis, and the erection ends. Tadalafil prevents phosphodiesterase-5 from destroying cGMP so that cGMP stays around longer. The persistence of cGMP leads to a more prolonged engorgement of the penis with blood.
The mechanism whereby tadalafil improves the symptoms of BPH is not clear, but phosphodiesterase-5 also is present in the muscles of the bladder and the prostate, and it has been suggested that the relaxation of these muscles may make the passage of urine less difficult, for example, by reducing the pressure in the muscle surrounding the opening to the urethra that controls the flow of urine from the bladder. Tadalafil was approved by the FDA in November 2003.
What brand names are available for tadalafil?
Is tadalafil available as a generic drug?
GENERIC AVAILABLE: No
Do I need a prescription for tadalafil?
What are the uses for tadalafil?
What are the side effects of tadalafil?
The most common side effects of tadalafil are
- facial flushing (reddening),
- stomach upset,
- flu-like symptoms, and
- Tadalafil also may cause low blood pressure,
- blurred vision,
- changes in color vision, and
- abnormal ejaculation.
Quick GuideErectile Dysfunction (ED) Causes and Treatment
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